New water facts provide State Government with golden opportunity

Camera IconThe McGowan Government has an opportunity to capitalise on new water findings in the Kimberly region.Picture: Illustration: Don Lindsay

It was only eight years ago that a report by the CSIRO was used by the Rudd Labor government to tell Australians that the long-held dream of the north becoming an important agricultural region was impossible because there wasn’t enough available water.

Anyone who was interested didn’t have to scratch too deep to establish that Rudd’s 17-month long Northern Australia Land and Water Taskforce was a political con-job meant to buy off the Greens and some Aboriginal groups.

Unfortunately, far too few were interested enough to investigate how the task force report came to its peculiar conclusions.

It misused a CSIRO report, Northern Australia Sustainable Yields, which even the agency admitted was based on “a paucity of quality data for water resource accounting.”

“This project was a desktop study,” the CSIRO said. “While no new data were collected, new data were generated through numerical modelling using existing data as a base, and new interpretations of existing data were undertaken.”

As I wrote in a column in February 2010, the best way not to find water was not to look for it.

Having been helped by the CSIRO to remain uninformed, the task force then did what many always suspected was its purpose.

What we have found out this week is that when politicians say the science is settled on certain issues, the public should be very wary.

The CSIRO’s new report, Northern Australia Water Resource Assessment, is an honest piece of work that turns the Rudd sham on its head.

This time, a team of more than 100 scientists worked for two-and-a-half years to identify six dam sites across Queensland and the Northern Territory and a major borefield in the Fitzroy River basin in WA.

The key findings of the new assessment are:

In the Fitzroy catchment, water harvesting could potentially support 160,000ha of agriculture, growing one dry-season crop a year in 85 per cent of years. Independent of surface water, groundwater could potentially support up to 30,000ha of hay production in all years for livestock feed.

In the Darwin catchments, involving the Finniss, Adelaide, Mary and Wildman rivers, a combination of major dams, farm-scale off-stream storage and groundwater could support up to 90,000ha of dry-season horticulture and mango trees.

In the Mitchell River catchment in Queensland, big dams could potentially support 140,000ha of year-round irrigation. Alternatively, water harvesting could enable up to 200,000ha, growing one dry-season crop per year.

“If irrigated opportunities were pursued to their fullest extent they would only occupy about three per cent of the assessment area,” the report says.

“Impacts on ecological function are not confined to the direct development footprint and would warrant attention, especially immediately downstream of development and in drier years.”

So the last point highlights — as anyone who has followed agricultural projects on the Ord River or at places like Humpty Doo in the Northern Territory knows — that developing these areas is difficult.

But that didn’t stop the politicians from immediately over-selling it.

Northern Australia Minister Matt Canavan claimed the CSIRO report paved the way for the construction of the “next great food bowl in our nation”.

For West Australians, most interest will be in the findings for the Fitzroy Valley, as was the case in 2010. In fact, Rudd made a long-time opponent of damming the Fitzroy, Bunuba leader Joe Ross, the chairman of his task force, immediately identifying its aims.

The new assessment does not propose dams, but is built around the use of borefields in the Fitzroy River catchment which was also the basis for former premier Colin Barnett’s ill-fated water canal idea that exploded his election campaign in 2005.

The report says the Fitzroy flows more than 700km from its upper reaches to King Sound. About 95 per cent of the catchment already supports pastoral uses and there is a population of only 7500 people.

“The Fitzroy catchment has up to 5.4 million hectares of potentially irrigable agricultural soils,” the CSIRO found.

“Of this land area, 4 million hectares are suitable for spray irrigation of cereals, between 400,000ha and 590,000ha for furrow irrigation of cereals, 2.8 million hectares for spray-irrigated sugar cane, and about 400,000ha for sugar cane with furrow irrigation.

“For aquaculture, such as prawns and barramundi, about 55,000ha of land are suitable using lined ponds.”

The study found up to 120 gigalitres a year of groundwater, which is less than 5 per cent of the catchment’s recharge, could be extracted from the sandstone aquifers.

“Under a wet season sowing on loamy soils, this volume of water could irrigate about 20,000ha of a crop such as cotton at an annual gross value of production of approximately $90 million, creating about $140 million of regional economic activity recurring annually and the generation of about 560 jobs,” the report said.

There was another 50GL/pa of available groundwater that would allow many small to medium-scale developments suited to irrigated forage production, each using between one and 5GL.

“It is physically possible to pump 1700GL of water in 85 per cent of years from major rivers and tributaries in the Fitzroy catchment into ringtanks near agricultural soils,” the report said.

“This volume of water would fill 425 ringtanks (each 4GL) and cost approximately $935 million. This would enable 160,000ha of clay soils under dry-season cotton to be irrigated.

“This could generate an annual gross value of production of approximately $750 million, and the region would benefit from $1.1 billion of annual economic activity and the generation of about 4700 jobs.”

There is no doubt that the usual suspects will immediately begin work to knock this opportunity on the head. GetUp! came out against it within hours of its release.

The WA Government was a partner in the study.

It will be a test of Premier Mark McGowan’s Government and especially Alannah MacTiernan as Minister for Regional Development, Agriculture and Food if they are willing to pursue real economic growth in the Kimberley.